You wouldn’t expect it from the mainstream, certainly. As with lots of things within a religious tradition as diverse and contested as Judaism, you’ll find a few people making the argument that Jews used to do it and should do it again. But my experiences weren’t with that kind of radical proselytizer. They involved reasonably mainstream Jews under extenuating circumstances. 
First: I was used to being approached on my college campus by Chabad proselytizers, who would wave me on when they found out I wasn’t their target audience. One day though, to my surprise, the response to “No, I’m not Jewish,” wasn’t “Have a nice day,” but “Great, we’ve got something for you too.” And out came the tract about the Noahide Laws, and a brief explanation of what I had to do to achieve righteousness as a Gentile. Lovely little chat.
Of course they weren’t suggesting I become Jewish…but as they were suggesting I change my behavior to fit a religious standard, I’d still count it as an example of proselytism. (Especially given the centrality of orthopraxy rather than orthodoxy in the religious tradition of the proselytizer in this case.) Not all proselytism has a change of religious self-ascription as its main aim.
(I also witnessed a truly impressive feat of Chabad proselytism, back when they used to host the world’s largest Passover seders here in Kathmandu every year to attract all the Jewish backpackers traversing South Asia–but for that one I was definitely just an observer, as my friend and traveling companion Rachel was the real object).
More straightforwardly, once in college when I was lamenting the inability of Christians to get it together, and making several favorable contrasts with (a maybe slightly romanticized version of) Judaism, one of my friends told me that if I was seriously attracted to what I’d just described, he’d be happy to help me convert. I didn’t ultimately take him up on it…but I was grateful for the offer, and for his sharing more of what his Judaism meant to him.
So that one was a case of proselytism by invitation. But then effective proselytism usually is, no matter what the religion.
Comparisons to the South Asian experience of caste are understandable, but I don’t want the religion driving the Karagond caste system to be mistaken for Hinduism. As I said on another thread:
Responding to some other points: Halassurqs don’t sacrifice women once they’re past childbearing years. I don’t think I’ve ever said that, and retract it if I did. But they do have a strong pro-natalist policy, in which women of childbearing age are expected to bear as many children as possible. This isn’t because most of the kids will be sacrificed–the firstborn usually suffices–but because the war consumes so many lives. The lack of Wards on the Halassur side mean that a lot more people die there than even in the horrible border areas of Erezza.
Halassur does use Theurgy for agriculture to sustain its large population. But they overall need a significantly lower blood volume, and would need markedly less if the war with the Thaumatarchy ended. Of course, one hope of many Halassurq generals (and perhaps the Emperor) is that if they do finally defeat Karagon, they’ll learn the secrets of some of those distinctively Hegemonic Theurgic feats like ward-building and mountain-floating, and scale up their blood economy by mass-Harrowing the Karagonds, Erezziano, and anyone else who doesn’t fall in line.
In answer to your later question, yes, you can make aetherial blood that really is just blood, but (as you’ll find out while cooking it in Game 2) it takes a LONG time to build up a quantity that allows you to do much of anything. If you tried to harvest “liberty blood” at national scale, you’d have an entire population staggering around sick all the time from daily bloodletting and you still wouldn’t have enough to replicate a fraction of the stuff that either Halassur or the Hegemony currently manage.
It is, and I’m not sure whether full-on modern individualism is plausible…but we’ll see. Some loosening of strict class-based ideas of telos in favor of individual variation will certainly be possible.